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[unix-history] / usr / src / libm / hypot.c

/*
* sqrt(a^2 + b^2)
*      (but carefully)
*/

double sqrt();
double
hypot(a,b)
double a,b;
{
       double t;
       if(a<0) a = -a;
       if(b<0) b = -b;
       if(a > b) {
               t = a;
               a = b;
               b = t;
       }
       if(b==0) return(0.);
       a /= b;
       /*
        * pathological overflow possible
        * in the next line.
        */
       return(b*sqrt(1. + a*a));
}

struct  complex
{
       double  r;
       double  i;
};

double
cabs(arg)
struct complex arg;
{
       double hypot();

       return(hypot(arg.r, arg.i));
}